Master sheet for use in making lithographic printing surfaces and method of making the same



A. GRASS.

THOGRAPHIC PRINTING SURFACES AND MET MAKING THE SAME. APPLICATION FILED JUNE 8,1918.

HOD OF MASTER SHEET FOR USE IN MAKING LI Patented May 23, 1922.

THIS IS A TRAN SLUCENT IMPRESSION SH EET INVENTOR. radd Fly. 2.

ATTORNEY umTEo STATES PATENT OFFICE.

ALFRED oEAss, on NEW YORK, N. Y., ASSIGNOR T0 AMERICAN can COMPANY, on

NEW YORK, N. Y., A conromvrron on NEW JERSEY.

IMASTER SHEET FDR. USE IN MAKING LITI-IOGRAPHIC PRINTING SURFACES AND METHOD OF MAKING THE SAME.

Specification of Letters Patent. Patente d lua 23 1922 I Application filed June 8, 1918. Serial No. 238,970.

To all whom it may concern:

B it known that ALFRED GRAss, citizen of Great Britain, residing at New York, in the county of New York (#467 West 22d St.) and State of New York, has invented certain new and useful Improvements in Master Sheets for Use,v in Making Lithographic Printing Surfaces and Methods of Making the Same, of which the following is a specification.

This invention relates to the production of a translucent or transparent master sheet for use in the preparation of printing surfaces, and'has for its objects to simplify and of such surfaces or plates, and also the printing process, and to provide for permanently cheapen and greatly improve the qualities preserving the text, pictorial or other composition which has been printed, in such form that it can be used again repeatedly to produce additional printing plates, registerlng in each instance the same clear and well defined photo impression on sensitized lithographic (metal or stone) surfaces as wasproduced on the first printing surface, and also producing flexible master sheets for color work that can be stored away and used at any future time and give perfect register for the different color plates, the treatment of the translucent sheets rendering them so nearly moisture proof that there is no appreciable change in their size orshape due to contraction or expansion incident to ordinary climatic changes, and which occupy a very small space and may be conveniently filed or stored away as fiat sheets safe from injury or deterioration.

With such objects in view, as well as other advantages which may be incident to the use of the improvements, the invention consists; in the procedure, and in theparts and combinations thereof hereinafter set. forth cations,

and claimed, with the understanding that the several necessary elements constituting thesame may be varied in proportions and arrangement without departing from the na-" ture of the invention,

In order to make the invention more clearly understood there are shown in theaccompanying drawings means for carrying the same into practical effect, without limiting the improvements in their useful appliwhich, for they purpose of explanation, have to the particular constructionsdotted lines. One corner of one of the im-' pression sheets is pulled over to show "it more clearly.

Referring to the drawing/l represents a sheet of tissue paper or equivalent material that is preferably a paper known as silver tissue used for wrapping and packing silverware. This is coated on both sides with a composition consisting of approximately five parts of translucent' var nish, one part of translucifying oil such as boiled linseed oil and two and one-half parts of turpentine or its equivalent, the indicated proportions being somewhatvaried to secure proper drying, whether the air be more or less charged with moisture, which sheet, when dried, will be translucent to a high degree, with a smooth surface for receiving ink and adapted to be applied over a lithographic surface or plate having thereon a grained surface and a sensitive photographic film, so that the text, (pictorial design or other mattercontaine on the sheet 1 may be printed by light on the film ofsaid plate. The matter which it is desired to print having been set up in type, the form of type is inked, and

the sheet 1 is impressed thereon so that the by rubbing the same with an evenly comminuted powder such as talc, powdered magnesia or other equivalent. After said impression has been made, the surface of the sheet is dusted with an opaque powder such as raphite, lamp black, bronze, silver or Indian red, which opaque powder will adhere to the ink of the impression and render the same entirely opaque for the said light printing operation. Then the excess of powder is dusted off, the tale, magnesia or its equivalent, rendering the sheet smooth and non-absorbtive, so that no opaque powder will remain excepting that adhering to the inkv impression, and the sheet will be clearly translucent in contrast with the ,entirely it plurality of the impression sheets 1 2c the small. impression sheets 1 on the large a to cover :tull

v i J- on treated with toe oil. and then out n i 'Mtnlates for s'uitahly printing the same design t nish loiy aid of an air 'brushso as not to blur impair the design and so to protect make permanent any subsequent use of the inked and opaqued parts. A. backing or supporting sheet 2 of bond paper, or other to suitable fibrous sheet material, is coated With composition consisting oil approximately equal parts of neat scloot oil and turpentine l "talent, and is thorough ,This sheet. 2 to. is a suitable mount,

duce' th plurebra laree roaster sheet ca H a Q 1,

7 l. ressions as printing 1:. urn i 'oducing the l1t' ographic printing suriace, in inountii hacking sheets 2, the side of each of the sheets coming in contact With another sheet is coated With a suitable thin volatile varnish, preferably an arnel acetate mastic 25 varnish, when they are pressed together squeegee d and left until set dried. Any number of small designs can he set up onthelarge sheet, as shown by dotted lines on Fi. 2,, and photographic film negatives D so may be used interspersed "with the printed matter if desired, and various features of printed matter may be combined together in thus producing the roaster sheet. The sheet 1 may be of the same size as sheet 2,

35 or sheet 1 may be used Without mounting on a hacking sheet the design is large enough A is size panting surface sired ln the production of the small inipression sheets 1, a large sheet is P smaller impression sheets to accoinrhooate the area of the lrnpressions to be mounted on the hacking sheet to produce the multiple impression master sheet. The impression a sheets 1 are usually applied to the sheet 2 With/their printed surface up, so that the design surface comes in as close con act possible With the sensitive iihn ct t ographic surface when the photo printing 1 m to he done so as to give the maximum sharpness, In applying photo ms to a hashing; sh 2 the emu sion :ulro is remover no i a contrast stripping Wet or dry plate, which has been suitably exposed and developed. 5 An important advantage oi this invention resides in the easy and perfect manner lay which What called resetting may be acc oinplished Resettingroeans readjustingor repl acif a impressions l on a backing or 3 on supportingsheet 2, giving impressions a Wider or narrower spacing" as may he necessary to accommodate diilerent sizes of to he printed with the same design, or for roaster sheets "from which to produce e1 flat material. to he folded into other sizes of boxes or cartons, or instance, the same impression is frequently applied to the covers or sides of difi erent size packages of the same class. lit applied to a larger package than the original layout was made for, it becomes necessary to increase spacing of the impression sheets 1 on the backing sheet 2, and if applied to smaller packages than the original layout was intended. for, it becomes necessary to reduce the spacing of the impression sheets 1. ll accomplish by a c i sheet '1 out the impressions l secured thereto and cut it up so that each 1 impression becomes individual to ession sheet These individual pres sions are then. inoun on a second hacking sheet exactly similar to sheet 2 when new master sheet is produced having the in ressions spaced to suit the new requir printing, and since all of these sheets are translucent, the triple thickness of paper gives as perfect results in printing onto the litho plate as the double thickness master sheets produce. 7 i

This invention is related to that described in my Patent 1,333,54 granted March 9, 1 920, and the procedure may he such as set forth in said application, except as modified according to my present improvements.

, /V is claimed is:

translucent master sheet for the duction of lithographic printing surfaces, comprising a fibrous sheet treated. to render it translucent moisture resistant, and h thereon a design in lightobstructing color, said sheet being attached to a trans 7 nacln: n sheet treated said .g sheet A close said design,

2. A. translucent master sheet, for the pro duction oi? lithon'raphic pr'.-ting surfaces, consisting or" a tissue sheet treated with varnish, oil, turpentine and talcum powder carrying opaque designs, a mountsheet tre ted with neat. cioot oil and turpentine, SZJLQ SHQEEtS being adhered together to enclose said opaque designs by the hi t Tcentine Yar ish. I

A. n d or rushing roaster sheets for the production of lithographic printing surfaces, "which consists in treating a tissue sheet with oil and a drier, treating a mount ing sheet with neats-foot oil and turpentine, applyingopaque designs on said tissue sheet and adheri. g; together said tissue sheet and said moo... g sheet Wl said designs in contact with the adhereo surfaces.

i A. method of making roaster sheets for the production oft" lithographic printing surztaces, hich consists in treating a tissue sheet W1 h varnish, boiled linseed oil turpentine, drying the same, dusting the .M

r Mer -ed together to insame with talcum powder, applying an opaque design on said sheet, dusting said design with powdered lamp black, varnishing over the design by an air brush; treat 5 ing a mounting sheet with neat's-foot oil and turpentine and drying the same, and

adhering together said tissue sheet and said mounting sheet by the aid of a thin turpentine varnish.

10 5. A translucent master sheet for the pro- ALFRED GRASS. 

